Development and validation of crosswalks between the EORTC QLQ-C30 physical, role, social and emotional functioning, fatigue and global health status/ quality of life scales and their corresponding PROMIS scales

Objectives: Across patient-reported outcome measures (PROMs), the European Organization of Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) is one of the most widely used among patients with cancer. Patients may also complete other PROMs such as forms of the Patient-Reported Outcomes Measurement Information System (PROMIS). The objective of this study was to develop crosswalks between the EORTC QLQ-C30 physical, role, social and emotional functioning, fatigue and global health status/quality of life (QoL) scales and their corresponding PROMIS scales. Study Design and Setting: In a single group-design, using the Netherlands Patient-Reported Outcomes Following Initial Treatment and Long-term Evaluation of Survivorship (PROFILES) registry, patients of various cancers were invited to complete the EORTC QLQ-C30 and PROMIS forms from September to December 2022. Data were randomly divided into a calibration and validation set. Crosswalks were developed using equipercentile equating and their predictive performance was assessed in terms of standardized mean absolute errors (SMAEs) and intraclass correlations (ICCs). Results: The total sample consisted of 1972 cancer patients (mean age 61 years; 55% female). We developed 15 crosswalks. Their SMAE was generally satisfactory (below 0.50) and comparable in the calibration and validation datasets. The highest precision was found for the physical functioning and fatigue crosswalks, followed by role functioning, emotional functioning and depression. The lowest precision was found for the EORTC QLQ-C30 to PROMIS general health, general QoL, and anxiety scores. Almost all ICC were above 0.70, except for EORTC QLQ-C30 to PROMIS anxiety/depression and PROMIS to EORTC social functioning. Conclusion: We developed valid crosswalks for multiple scales of the EORTC QLQ-C30 and PROMIS. The established concordance tables can be used to convert scores in both directions and are valid for group level analyses. The crosswalks from EORTC emotional functioning toward PROMIS anxiety and depression demonstrate suboptimal performance and should therefore be used carefully.